Q. A circular conductor of radius 5 cm produces a magnetic field of $7 \times 10^{- 6}\ T.$ The current flowing through the conductor is
A) 3.0 A
B) 2.25 A
C) 4.5 A
D) 0.56 A
Explanation
(d) $B = \frac{\mu_{0}}{4\pi}\frac{2\pi i}{r}$
or $7 \times 10^{- 6} = \frac{10^{- 7} \times \ 2\pi\ \times \ i}{5\ \times 10^{- 2}}$
$i = 0.56\ \mathring{\mathrm{A}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.